1. Field of the Invention
The present invention relates to a method and apparatus for cleaning a master disk and, more particularly, to a cleaning technique suitable for removing dust attached to a master disk for transfer of magnetic information such as format information to a magnetic recording medium used in a hard disk unit or the like or a master disk used for nanoimprinting.
2. Description of the Related Art
In recent years, it has been a common practice to write format information and address information to a magnetic disk (hard disk) for use in rapidly-widespread hard disk drives before the magnetic disk is incorporated in a drive after being supplied from a magnetic disk maker to a drive maker. This writing may be performed with a magnetic head. However, a method of (magnetically) transferring such format information and address information at a time from a master disk on which the information is written is effective and preferable.
In this kind of magnetic transfer technique or nanoimprinting technique, there is a need to maintain a master disk (transfer original disk) and a slave disk (transfer-destination medium) in closely-contacted state. If the degree of cleanness in the transfer environment is low, there is a problem that fine particles, dust or the like cause transfer failure or scratches or the like on the surface of the master disk.
As cleaning techniques, CO2 cleaning, tape varnishing, a method of moving a foreign material by bringing a master disk into close contact with a substrate with NiP plating (dummy disk) (Japanese Patent Application Laid-Open No. 2001-176065), air blowing, plasma cleaning, scrub cleaning, ultrasonic cleaning, jet cleaning, a method using a cleaning roller (self-adhesive tape) (Japanese Patent Application Laid-Open No. 48-35771, Japanese Patent No. 3346660) and other techniques are known.